DE 10 2005 045 036 A1 specifies a multispectral camera and a method for generating image information using a multispectral camera.
In digital camera systems with a plurality of independent cameras or camera heads, which have shutters and corresponding digital sensors for defining the light quantity to be recorded or the exposure time, it is possible for the individual cameras to deviate from one another as a result of production-dependent scattering in the shutter and sensor behavior.
In a multispectral camera, in which the individual or separate or independent camera heads each record light of an image of the same scene in different spectral or wavelength regions, which are separated by corresponding upstream color filter elements, more particularly as a result of a simultaneous or synchronous image recording by all camera heads, in which the image signals are subsequently combined to form a multispectral image, the same light quantity or exposure time during the image recording should where possible accrue for all independent camera heads. It is for this reason that the aforementioned deviations or tolerances caused by the slightly different exposure times of the individual camera heads can disadvantageously lead to color casts in the multispectral image.
It is common practice to use position sensors or the like to carry out approximate measurements in respect of the actual exposure times of the individual camera heads and already use this to calculate approximately a necessary color balancing. However, it proves impossible to undertake more precise estimations as a result of the different light quantities or image information, which are caused by the different color channels or color filters in the individual cameras.